GB2116315A

GB2116315A - Ash fusion analyzer

Info

Publication number: GB2116315A
Application number: GB08305978A
Authority: GB
Inventors: Larry S O'brien; Ward S Kaler
Original assignee: Leco Corp
Current assignee: Leco Corp
Priority date: 1982-03-05
Filing date: 1983-03-04
Publication date: 1983-09-21
Also published as: DE3302019A1; GB2116315B; GB8305978D0; JPS58162849A; DE3302019C2; US4522787A

Description

1 GB 2 116 315 A 1

SPECIFICATION Ash fusion analyser

This invention relates to analytical devices, and more particularly to analytical devices for determining the fusibility of coal and coke ash.

Before coal or coke is burned in a furnace, the fuel should be analyzed to determine the fusibility of the coal or coke ash. Burning coal or coke is a commercial steel mill furnace, which generates temperatures sufficiently high to use the ash, 75 causes the ash to collect on various furnace components, most notably the furnace grates. If collection becomes excessive, the furnace must be shut down, cooled, and cleaned, requiring excessive periods of furnace inactivity.

The ASTM standard test method for determining the fusibility of coal and coke ash requires the ash to be formed into triangular pyramid cones which are placed within an analytical furnace. The temperature within the furnace is then ramped at 8.331C (1 50F) per minute, and the cones are manually observed to detect changes in shape. The fusibility of the ash is reported in four temperatures; namely, 1) the temperature at which the apex of the cone 90 becomes rounded, 2) the temperature at which the height of the deformed cone is equal to the width of the base, 3) the temperature at which the height of the deformed cone is equal to one-half the width of the base, and 4) the temperature at which the cone has been reduced to a lump having a height no greater than 1.59 mm (one sixteenth inch). This test method has several significant drawbacks. First, the method is time consuming and requires an observer to constantly monitor all cones within the furnace as all cones pass through all four stages of fusion. This task is boring and the observer can become inattentive, resulting in inaccurate temperature readings.

Second, monitoring the shape of five cones (the typical furnace load) is difficult. Third, the empirical findings are somewhat subject to the individual judgement of the human observer, further introducing error and variation into the test results. The ASTM test method recognizes these problems and provides for relatively large acceptable errorfor each of the four stages of fusion in excess of 500C or 1 OOOF.

Although at least two known devices have been developed in an attempt to reduce the time consuming and tedious chore of observing the cones, these devices are not without their drawbacks. One such device is sold as an add-on unit for conventional furnaces and comprises a closed circuit camera and monitor and a video tape recorder coupled thereto. The operator initiates the test and activates the video tape recorder to make a record of the analysis run. After the test is complete, the operator may replay the tape at a relatively rapid speed to determine the fusibility criteria for each cone. However, this equipment and method is still subject to the individual judgement of the operator in evaluating cone shape. Further, reviewing the entire video tape after a test run is just as tedious and boring as watching the test itself.

Another known device is also sold as an add-on unit for conventional furnaces and includes a closed circuit camera and a computer coupled thereto to analyze the video image on the camera. However, as well as in the above-described unit, the vidicon tubes provide poor performance under the high light intensity of the white-hot cones and the furnace interior. Second, the vidicon tubes frequently burn out due in part to the high light intensities involved. Third, the computer required to analyze the video image, and the software implementing the analyzing procedure is relatively complicated since the computer must distinguish and separately analyze each of the individual cones (typically five) within the furnace which are present in the single video image.

According to one aspect of the present invention, an analyzer furnace comprises: a furnace defining a chamber; radiation responsive detection means for producing signals responsive to an image focused thereon; means for projecting the image of a portion of said furnace chamber onto said detection means; and means for supporting one or more samples within said furnace chamber and for repeatedly conveying said samples through said chamber portion, whereby the images of said samples are repeatedly projected to said detection means.

According to a second aspect of the invention, an ash fusion analyzer comprises: a furnace including a chamber for the fusion of one or more samples therein; detection means positioned remote from the chamber for producing signals responsive to an image projected thereon; means for projecting the image of a portion of the furnace chamber onto said detection means; means for supporting one or more samples within said furnace chamber and for repeatedly conveying said samples through said chamber portion, whereby the image of said sample is repeatedly projected on said detection means; and circuit means coupled to and respective to signals from the detection means for calculating shape information relating to the shape of said sample.

According to a third aspect of the invention, an ash fusion analyzer comprises: a furnace having a temperature-controllable chamber; platform means for supporting one or more samples within said chamber; line scan means for sampling light intensity along a line and producing signals responsive thereto; means for projecting repetitive images of each sample onto the line scan means; computer means coupled to the line scan means for sampling the said signals as the said images are projected onto the line scan means and for calculating sample shape information; and display means for displaying the said shape information.

In a preferred embodiment of the invention, the line scan means comprises an array of solid-state devices including a plurality of light-sensitive diodes arranged in a linear configuration. Additionally, in the preferred embodiment, the cone image scanning means includes means for 2 GB 2 116 315 A 2 rotating the platform to provide image movement.

Because the cone images are individually scanned across the line scan array, the computer can simply sample the line scan array as the image passes thereby to quickly determine the current shape of any cone by stepwise integration. This greatly reduces the computer hardware and software required to implement shape analysis. Second, it is possible to construct the analyzer so that the operator is required only to initiate the system and load and unload samples. This leaves the operator free to operate similar analyzers or other equipment within the laboratory. Third, the tedium of visually continuously observing the cones is eliminated. Fourth, variations produced by the individual judgement of the operator in determining stages of fusibility are also eliminated, being implemented by solid-state devices and computer analysis.

In the preferred embodiment of the invention, the solid-state imaging device has a far longer life under the intense illumination involved than video cameras previously used. This not only improves the reliability of the system, but reduces the need for maintenance and repair.

The invention may be carried into practice in various ways but one ash fusion analyzer embodying the invention will now be described by way of example with reference to the accompanying drawings, in which:

Figure 1 is a perspective view of the ash fusion analyzer; Figure 2 is a top plan view, partially broken away, of the analyzer; Figure 3 is a vertical, cross-sectional view of the furnace and sample pedestal; Figure 4 is a view taken along plane IV-IV in Figure 3, Figure 5 is a side elevational view of the pedestal transportation mechanism; Figure 6 is a top plan view of the structure shown in Figure 5; Figure 7 is a top plan view of the furnace and optical assembly; Figure 8 is a cross-sectional view taken along 110 plane VIII-VIII in Figure 7 and the inverted image focused on the line scan array; Figure 9 is a front elevational view showing the line scan array; Figure 10 is a fragmentary, exploded, side 115 elevational view of the sample tray and sample pedestal; Figure 11 is a top plan view!Aen along plane XI-XI in Figure 10; Figure 12 is a side elevational view illustrating 120 the stages of fusion for a cone sample; and Figure 13 is an electrical circuit diagram in block form showing the control system for the analyzer.

The ash fusion analyzer 10 shown in Figure 1 125 includes a housing 12 and a furnace 14 supported within the housing. The furnace has a furnace chamber 15 (Figure 3) with a viewport 17. A sample pedestal 16, sample transportation mechanism 18 supporting pedestal 16, and an optical assembly 20 are also supported within the housing with assembly 20 aligned with the viewport. Mechanism 18 transports pedestal 16 between an analyze position (see Figure 3) wherein a sample tray 92, in pedestal 16, is positioned within furnace chamber 15, and a load position (see Figure 1) wherein the pedestal is positioned for loading and unloading. When in the analyze position, pedestal 16 is rotated to convey the cones 21 supported thereon past viewport 17. Optical assembly 20, as seen in Figure 7, includes a mirror 22 and lens 24 which directs and focuses the images of cones 21 within chamber 15 onto a line scan array 26. A computer 28 (Figure 13) is coupled to line scan array 26 and repeatedly samples the line scan array as the cone images are scanned thereacross to calculate information regarding the present shape of the cones. This cone-shape information is then analyzed to calculate ash fusibility.

Turning more specifically to the construction of the analyzer 10 (Figure 1), the housing 12 includes a keyboard 30 coupled to a computer 28 (Figure 13) for inputting control command information. Additionally, housing 12 suppoits a display 32 panel with a display also coupled to computer 28 to indicate information regarding the temperature within the furnace 14 and the shape of the cones therein.

Furnace 14 (Figure 3) is generally cylindrical and supported within housing 12. The side wall of - furnace 14 includes an outer liner 34, middle liner 36, inner liner 38, and a heating element support 40. Liners 34, 36, and 38 are cylindrical and 1 include diametrically opposed viewports, or cylindrical bores, 17 and 41, extending r3dially therethrough. The bores are covered by single crystal alumina or quartz windows 1 7a and 41 a, respectively. Viewport 41 is visible through a smoked- glass front panel 33 (Figure 1) while viewport 17 is generally aligned with optical detector 20. The furnace includes a floor 42 and hearth 44 supported thereon. Floor 42 and hearth 44 together define a stepped bore or aperture 45 which receives pedestal 16. A gas bore 47 is formed in floor 42 and hearth 44 through which gases can be introduced into chamber 15. A gasket 46, cover 48, and top plug 50 comprise the upper portion of furnace 14. All of the furnace components thus far described, are dimensioned to closely interfit with one another to provide a relatively tightly closed chamber 15, having a volume of approximately three litres. A plurality of generally U-shaped heating elements 52 extend between element support 40 and gasket 46 and downwardly into furnace chamber 15 so as to be oriented generally parallel to the furnace side wall. Elements 52 are driven by a power source 116 (Figure 13) coupled to computer 28 by suitable interface circuits included as part of circuit block 28 of Figure 13. A ceiling member 54 and spacer 56 (see also Figure 4) cooperate to sea[ elements 52 within furnace 14.

Transportation mechanism 18 (Figures 5 and 6) 130 includes a rodless cylinder 58 actuated by an 4 3 GB 2 116 315 A 3 up/down switch 11 in a conventional manner, a supporting bracket 60, and a support 62, pivotally mounted on the bracket by a pin 68. Cylinder 58 is secured within housing 12 (see Figure 2) by securing brackets 64, which extend from the cylinder, to the housing. Vertically shiftable element 66 extends from cylinder 58 to travel upwardly and downwardly thereon. Bracket 60 is secured to element 66 by bolts 67. Accordingly, support 62 can pivot in a horizontal plane about pivot pin 68 and can be vertically shifted by actuating cylinder 58 to raise or lower element 66 and bracket 60 supported thereon.

A motor 70 is supported on the underside of support 62 and drives a shaft 72 at approximately 80 ten r.p.m. Worktable 74 is supported in overlying relationship on support 62 and in turn supports sample pedestal 16 and a sensor 76. The sensor is a conventional optical sensor capable of directing light toward an object and sensing the reflectivity 85 of the object against which the light is directed.

Sensor 76 is coupled to computer 28 (Figure 13) to provide rotational positional information regarding pedestal 16.

Pedestal 16 includes a stepped refractory portion 78 which in turn includes a lower cylindrical portion 80 and an upper cylindrical portion 82 having a diameter somewhat smaller than the lower portion to generally conform to bore 45. A generally planar sample platform 84 is defined by the upper end of upper portion 82. Pegs 98 and 100 (Figures 10 and 11) extend upwardly from platform 84, with peg 98 located at the centre of the platform, and peg 100 offset for indexing the sample tray 92 thereon.

The lower portion 80 of refractory element 78 is fixedly supported within an aluminium cup 86 which is fixedly mounted on drive shaft 72 for rotation therewith. Consequently, motor 70 rotates sample platform 84 through shaft 72, cup 105 86, and refractory element 78. Cup 86 includes a plurality of narrow, vertically extending, light reflective strips 90 extending around its perimeter surface 91. In the preferred embodiment, perimeter surface 91 is painted black, and 110 reflective strips 90 are formed by cutting away the black enamel at strips 90 to expose the reflective aluminium. One strip 90 is included for each cone sample 21 to be supported on platform 84 and in the preferred embodiment five such strips are 11 employed. Consequently, as pedestal 16 rotates, sensor 76 can detect reflective strips 90 as the strips pass by the sensor which generates signals responsive to the reflective strips and which indicate information as to alignment of the 120 samples with respect to port 17.

Sample tray 92 (Figures 10 and 11) is a generally disc-shaped element having an outer diameter identical to the outer diameter of upper portion 82 of pedestal 16. Tray 92 defines a plurality of circular depressions 93 each of which is approximately 6.35 mm in diameter and approximately 0.79 mm deep. Depressions 93 receive cone samples 21 sized in accordance with the ASTM standards. An aperture 94 extends through the centre of the tray 92, and an aperture 96 is located radially outwardly theref rom to mate with pegs 98 and 100, respectively, on the platform 84. Consequently, tray 92 may be placed on platform 84 in only one angular orientation to ensure the proper alignment of sample holding depressions 93 with indicator strips 90 on the aluminium cup 86.

Optical assembly 20, most clearly shown in Figure 7, includes a support tube 102 for supporting the mirror 22, in iris 104, the lens 24, and the line scan array 26. The support tube 102 is mounted to housing 12 and aligned with viewport 17 which is in turn aligned with sample tray 92 (Figure 3). Mirror 22 is supported at the junction of the portions 102a and 102b to project an image from viewport 17 through iris 104 and lens 24 along an optical path 23. This folded construction greatly improves the compactness of assembly 20. Both iris 104 and lens 24 are generally well known. Iris 104 is a fixed-aperture iris to control the intensity of the image focused on the line scan array. A variable-aperture iris may alternatively be used. Lens 24 is selected to focus the image from viewport 17 onto line scan array 26 such that cones 2 1, having a height of 19.05 mm are reduced to an image 114 (Figure 8) 3.175 mm high.

Line scan array 26 (Figures 7, 8, and 9) is, in the preferred embodiment, a solid-state, chargecoupled imaging device which is commercially available. As seen in Figure 9, array 26 includes a generally linear and vertical alignment with a total height of 6.35 mm of light-sensitive diodes 106.

In the preferred embodiment, 256 such diodes are employed in an integrated circuit chip, Model No. RL-256G manufactured by EG and G Reticon. Array 26 is positioned within tube portion 102b so that image 108 of viewport 17 is focused on the line scan array (Figure 8). Image 108 is in line scan array (Figure 8). Image 108 is in turn comprises of background image 110, platform image 112, and cone image 114. Because viewport 41 is relatively cool with respect to platform 92 and cones 2 1, background image 110 will appear to array 26 to be dark, or black, compared to platform and cone images 112 and 114. Platform 92 and cones 21 which are whitehot produce images 112 and 114 which appear light, or white, compared to background image 110. Consequently, the outline of cone 21 in image 108 is clearly defined. As pedestal 16 rotates, samples are conveyed through the portion of furnace 14 aligned with viewport 17 so that cone images 114 are scanned across line scan array 26. Further, because pedestal 16 continually rotates, the cone images are repeatedly scanned across the array.

A thermocouple 111 (Figures 7 and 13) is positioned within chamber 15 and coupled to computer 28. Thermocouple 111 senses the temperature within furnace 14 and generates signals responsive thereto which are received by computer 28 and used as part of a closed loop temperature control for the furnace.

4 GB 2 116 315 A 4 Figure 13 shows the overall computer control for analyzer 10. Computer 28 is coupled to line scan array 26, keyboard 30, pedestal sensor 76, and furnace thermocouple 111 by suitable interface circuits to receive signals therefrom. Additionally, computer 28 is coupled to display 32, pedestal motor 70, and element power source 116 by suitable control circuits to provide controlling signals thereto. Display 32 may show cone number, present fusibility stage, and the temperature at which the present fusibility stage was entered. Additionally, computer 28 may be connected to a printer (not shown) to provide a hard copy of information presented on display 32.

OPERATION The various fusibility stages to be evaluated by analyzer 10 are illustrated in Figure 12. The ASTM cone 112 is a pyramid having a triangular base 6.35 mm (one-quarter of an inch) on each side of the base and 19.05 mm (three-quarters of an inch) high. Cone 116 illustrates the cone in its initial deformation temperature wherein apex 118 is just rounded. Cone 120 is in the second stage, designated the softening temperature, wherein the cone has fused down to a spherical lump having a height equal to the width of the base. Cone 122 is at the hemispherical temperature wherein the height of the hemispherical lump is equal to onehalf the width of the base. Finally, at the fluid temperature. cone 124 is a fused mass having a maximum height of 1.59 mm (one-sixteenth inch). The ASTM standard requires all of these temperatures to be determined requires all of these temperatures to be determined for each sample.

When analysis is to be conducted, five separate cones can be analyzed simultaneously with each being formed in accordance with standard ASTM procedures. The five cones 21 are then positioned upright within depressions 93 on plate 92 with each cone seated within one of the depressions. Pedestal 16 is then moved to its loading position as illustrated in Figure 1, and sample tray 92 is positioned on platform 84 of pedestal 16 by aligning apertures 94 and 96 with studs 98 and 100, respectively, and placing the tray on the platform. Pedestal 16 is then moved to its analyze position within furnace 14 (Figure 3) so that sample tray 92 and cones 21 are vertically aligned with viewports 17 and 4 1. The operator then enters a suitable command on keyboard 30 indicating to computer 28 that an analysis is to begin. Computer 28 is conventionally programmed to develop appropriate control signals to element power circuit 116 to actuate elements 52 to elevate the temperature within chamber 15 to the initial temperature of 81 51C (15000 F), in the preferred embodiment. When the initial temperature has been reached as sensed by thermocouple 111, computer 28 generates a control signal to actuate pedestal motor 70 to rotate at 10 r.p.m. and to power source 116 to ramp the temperature within chamber 15 at 8.330C (1 51F) per minute. Additionally, ASTIVIspecified gases are introduced into chamber 15 through gas bore 42 in a conventional manner.

As pedestal 16 and sample tray 92 thereon are rotated, the cones are carried through the portion of furnace 14 aligned with viewport 17. The image of chamber 15 obtained through viewport 17 is reflected on mirror 22 and directed through iris 104 and lens 24 onto line scan array 26. Consequently, the images of the cones are repeatedly (at about 580 scans/second) and individually vertically scanned across line scan array 26 as pedestal 16 rotates. During analysis, computer 28 repeatedly samples array 26 by reading each of diodes 106 at a rate of 500 kHz from bottom to top until a light-to-dark transition is detected. Between cones, the sampling of line scan array 26 will establish the top of tray 92. The reflective strips 90 are positioned on the aluminium cup 86 so that sensor 76 will detect one of the reflective strips immediately prior to the entry of a cone into viewport 17. Each of reflective strips 90 is unique, so that sensor 76 will issue different signals to computer 28 each unique to one of the cones 2 1. Consequently, computer 28 is capable of determining which of cones 21 is about to be scanned across line scan array 26. In the preferred embodiment, the entire array 26 is sampled approximatley every 1.7 milliseconds to provide the desired resolution in determining the shape of cone image 114. The computer then analyzes the stored multiple scan information obtained upon one passage of an image 114 to evaluate the shape of the cone.

Computer 28 is programmed in a conventional manner to compare the temporarily stored scan information with stored data corresponding to the four fusibility stages by the following criteria. A cone is determined to have obtained its initial deformation temperature when the peak of the cone has shrunk 1.59 mm. The cone has attained its softening and hemispherical temperatures when the height is equal to the width of the base and one-half of the width of the base, respectively. Finally, the fluid temperature is attained when the height of the cone is no greater than 1.59 mm. As computer 28 determines that one of the fusibility stages has been attained, it stores this information including cone number, fusibility stage, and the temperature as sensed by thermocouple 111 at which the stage was entered into. This information 115, is displayed on display 32 and in the preferred embodiment is printed on a printer at the conclusion of the analysis to provide a hard copy of the analysis results. Because the temperature is ramped at 8.33'C per minute, and because pedestal 16 rotates at 10 r.p.m., the accuracy of each fusibility stage temperature is determined with an accuracy of +0.83'C (1.5'F). This accuracy is a vast improvement over the acceptable ASTM accuracy of +27.8'C (50'F).

When the temperature within chamber 15 has risen above the fluid temperatures of all of the cones on tray 92, computer 28 issues a control signal to element power source 116 to deactivate elements 52 and to deactivate pedestal motor 70.

A GB 2 116 315 A When the operator activates the cylinder up/down 65 portion, whereby the image of said sample is switch 11, the pedestal may be moved to its unloading position as shown in Figure 1 whereupon the sample tray 92 is removed from pedestal 16 and discarded. Analyzer 10 is then ready for the next analysis run.

Claims

1. An analyzer furnace comprising: a furnace defining a chamber; radiation responsive detection means for producing signals responsive to an image focused thereon; means for projecting the image of a portion of said furnace chamber onto said detection means; and means for supporting one or more samples within said furnace chamber and for repeatedly conveying said samples through said chamber portion, whereby the images of said samples are repeatedly projected to said detection means

2. A furnace as claimed in Claim 1 in which the sample supporting means comprises a sample 85 support device and means for rotating the device to move a sample within the chamber in a predetermined path of movement.

3. A furnace as claimed in Claim 2 in which the sample support device includes means for 90 indicating the angular orientation of each of the samples within the chamber.

4. A furnace as claimed in Claim 1 or Claim 2 or Claim 3 which includes circuit means coupled to and responsive to the detection means for 95 determining shape information of a sample.

5. A furnace as claimed in any of the preceding claims in which the projection means comprises a viewport extending through the furnace in alignment with the sample support device and optical means for focusing radiation from the viewport onto the detection means.

6. A furnace as claimed in Claim 5 in which the detection means comprises a solid-stage imaging device formed of a linear array of detection 105 elements.

7. A furnace as claimed in Claim 6 in which the array is a plurality of light-sensitive diodes sensitive to radiation within the visible spectrum.

8. A furnace as claimed in Claim 6 or Claim 7 which includes circuit means for scanning the array and producing signals responsive thereto which can be employed to provide a profile of samples passing the viewport.

9. A furnace as claimed in Claim 8 in which the 115 circuit means includes a computer for comparing information from the detection means with stored information and for providing output signals representing the existence of a comparison.

10. An ash fushion analyzer comprising: a 120 furnace including a chamber for the fusion of one or more samples therein; detection means positioned remote from the chamber for producing signals responsive to an image projected thereon; means for projecting the image of a portion of the furnace chamber onto said detection means; means for supporting one or more samples within said furnace chamber and for repeatedly conveying said samples through said chamber repeatedly projected on said detection means; and circuit means coupled to and responsive to signals from the detection means for calculating shape information relating to the shape of said sample.

11. An ash fusion analyzer as claimed in Claim in which the sample supporting means comprises a sample-supporting device and means for rotating the said device.

12. An ash fusion analyzer as claimed in Claim 11 in which the sample-supporting device includes means for locating each sample thereon and for indicating the angular orientation of each of the samples within the chamber.

13. An ash fusion analyzer as claimed in Claim 12 in which the a nalyzer fu rther comprises sensor means coupled to the circuit means for producing signals responsive to the indicating means for producing signals responsive to the indicating means, whereby the circuit means determines which of the samples is in the said chamber portion.

14. An ash fusion analyzer as claimed in any of Claims 10 to 13 in which the projection means includes a viewport formed through a wall of the furnace and enclosed by a window, the viewport being aligned with the said chamber portion.

15. An ash fusion analyzer as claimed in Claim 14 in which the projection means includes a focusing lens and a mirror to reflect images from the window onto said detection means.

16. An ash fusion analyzer as claimed in Claim 14 or Claim 15 in which the projection means includes an iris to control the intensity of the image on the detection means.

17. An ash fusion analyzer as claimed in any of Claim 10 to 16 in which the detection means comprises a solid-state imaging device.

18. An ash fusion analyzer as claimed in Claim 17 in which the solidstate imaging device comprises a generally linear array of lightsensitive diodes.

19. An ash fusion analyzer as claimed in Claim 18 in which the solidstate imaging device comprises a charge-coupled integratrated circuit.

20. An as fusion analyzer as claimed in any of Claims 10 to 16 in which the detection means comprises a line scan array of detectors.

2 1. An ash fusion analyzer as claimed in Claim 20 in which the array comprises a plurality of light-sensitive diodes.

22. An ash fusion analyzer as claimed in any of Claims 10 to 21 which includes means coupled to the circuit means for sensing the temperature within the chamber and producing signals responsive thereto.

23. An ash fusion analyzer as claimed in any of Claims 10 to 22 which includes display means coupled to the circuit means for displaying the said shape information.

24. An ash fusion analyzer as claimed in Claim 23 when appendant to Claim 22 in which the circuit means comprises a computer programmed for correlating sample shape information with the 6 GB 2 116 315 A 6 furnace chamber temperature.

25. An ash fusion analyzer comprising: a furnace having a temperature-controllable 30 chamber; platform means for supporting one or more samples within said chamber; line scan means for sampling light intensity along a line and producing signals responsive thereto; means for projecting repetitive images of each sample onto the line scan means; computer means coupled to the line scan means for sampling the said signals as the said images are projected onto the line scan means and for calculating sample shape information; and display means for displaying the said shape information.

16

26. An ash fusion analyzer as clairned in Claim 25 in which the line scan means comprises a linear array of light-sensitive diodes.

27. An ash fusion analyzer as claimed in Claim 25 or Claim 26 in which the projection means includes means for rotating the platform means.

28. An ash fusion analyzer as claimed in Claim 27 in which the platform means comprises means for indicating the angular orientation of each sample on the rotating platform means; and wherein the system comprises means coupled to the computer means for generating signals responsive to the said indicating means.

29. An ash fusion analyzer as claimed in Claim 25 or Claim 26 in which each of the samples is assigned a unique identifier and in which the display means displays the shape information for each sample in conjunction with the identifier assigned to each sample.

30. An ash fusion analyzer as claimed in any of Claims 25 to 29 which includes means coupled to the computer means for sensing the temperature within the furnace chamber and generating signals responsive thereto.

3 1. An ash fusion analyzer as claimed in Claim 30 in which the display means displays the shape information in conjunction with the temperature within the furnace chamber.

32. An ash fusion analyzer as claimed in any of Claims 25 to 31 in which the furnace includes wall means and the projection means includes a viewport formed through the wall means.

33. An ash fusion analyzer as claimed in Claim 32 in which the projection means includes a mirror, a lens and can iris positioned to define a folded optical pathway to focus a reduced sized image of a sample onto the line scan means.

34, An ash fusion analyzer substantially as described herein with reference to the,,a companylng drawings.

Printed for Her Majesty's Stationery Office by the Courier Press, Leamington Spa, 1983. Published by the Patent Office, 25 Southampton Buildings, London, WC2A 1AY, from which COP169 May be obtained.

4 1 X